Nicotinamide adenine dinucleotide (NAD) and its relative nicotinamide adenine dinucleotide phosphate (NADP) are two of the most important coenzymes in the cell. NADP is simply NAD with a third phosphate group attached as shown:

Because of the positive charge on the nitrogen atom in the nicotinamide ring (box), the oxidized forms of these important redox reagents are often depicted as NAD+ and NADP+ respectively.
In cells, most oxidations are accomplished by the removal of hydrogen atoms. Both of these coenzymes play crucial roles in this. Each molecule of NAD+ (or NADP+) can acquire two electrons; that is, be reduced by two electrons. However, only one proton accompanies the reduction. The other is liberated into the surrounding medium. For NAD, the reaction is thus:NAD++2H→NADH+H+
NAD participates in many redox reactions in cells, including those in glycolysis and most of those in the citric acid cycle of cellular respiration.
NADP is the reducing agent produced by the light reactions of photosynthesis, consumed in the Calvin cycle of photosynthesis and used in many other anabolic reactions in both plants and animals. Because NADP is used in anabolic reactions, it is desired to increase its levels in order to drive bacteria towards the synthesis of desired compounds.
The purpose of this invention is to manipulate the E. coli intracellular NADPH availability, which in turn increases the yield and productivity of NADPH-dependent synthesis of compounds, such as the biodegradable polymer poly-3-hydroxybutyrate (PHB), sorbitol, alcohols, amino acids, lycopene terpenoids, flavanoids, carotenoids, mevalonate, purines, pyramidines, antibiotics, cholesterol, steroids, and the like. NADP dependent compounds include fatty acids of varying chain lengths, or lycopene, which can be used as an antioxidant or precursor to produce other carotenoids. Increased NADP levels can also be useful for recycling some enzymes such as P450s, some of which require NADPH, and these can be active in drug metabolism and specialized oxidations. Additionally, chiral alcohols are products that often require reduction using NADPH. Thus, increasing NADP levels can be useful in a great many different contexts and applications.